Born on Robinson to parents, Mark and Pamela Sandoval, his mother died during childbirth. After two years, his father Mark brought Aaron back to the Republic on the planet Addicks. Some time later his grandmother CountessEdwina Sandoval joined them on Addicks and helped raise Aaron. During Aaron's infancy, his father returned to Republic politics as Addicks' Assistant Governor in 3107. Aaron's grandmother became important to him and gave him an early education in the world of politics.

Growing up, Aaron was influenced by his grandmother, and as a result pursued an education centered around politics. After going to a number of Republic schools, he went overseas to the Federated Suns world of Marlette in 3115 to study. At the Brighton Preparatory School, he quickly became friends with his cousin and the future First PrinceHarrison Davion. After time with Harrison, he was encouraged to excel in his education, especially in political science. He then attended the Republic's Sandhurst MechWarrior Academy from 3117 until 3120. When there, he tested well as a MechWarrior; he also went to the League University to pursue degrees in political science before entering the RAF military as part of his mandatory military service requirements.[2]

During his career with Republican Armed Forces, he served principally as military aide to Legates on Addicks. Despite his good performance as a MechWarrior, he was drawn into serving the military bureaucracy. However, he was drawn into active combat as part of a Task Force of Republican forces to combat and hunt down smuggling on the border. During the campaign he soon discovered that the pirates and smugglers were backed by members of his family from the Federated Suns during a battle on Schedar. He was instrumental both in secretly covering up his family ties in the pirate/smuggling activities and shutting them down. Publicly, it was unknown that his family was involved in the raids. His active combat role ended prematurely as he was pulled from duty to become aide to Prefecture VI's Legate Amanda Cross.[3]

In 3123, his father, then Count Addicks, died of a stroke prior to attempting a re-start of his career as a Republic Senator. His father's death proved to be a turning point that pushed Aaron to choose to get into politics after his mandatory time in the military ended.

At the end of his military service time in 3124, the Republic Military attempted to convince Aaron to remain with the Armed Forces; however due to personal reasons, Aaron chose not to in favor of a political career.[4]

During the early days of his career, he steadily rose in Addick's politics. He proved to be able to administrate well and he served as aide to Prefecture IV's Lord GovernorWilliam Sung. In 3127, Aaron was elected as Governor of Addicks, where he began efforts to spread his influence across the Republic's political scene. He built good will where he started projects that helped get non-citizen residents jobs. Through his efforts, the Immigrant Coalition Committee would allow him become the Lord Governor of Prefecture IV a year later.[5]

During his service as governor of Prefecture IV, Aaron worked hard toward his goals.

In 3130, Aaron appointed Kal Radick as Prefect instead of the experienced General Michael Sampson. General Sampson withdrew his candidacy and instead became Prefecture VI's training Commandant.[6]

Regardless of his efforts, Aaron made a number of enemies, including some on his homeworld of Addicks. CEO Jacob Bannson of Bannson's Bannson Universal Unlimited became a critic of Aaron due to the passing of an anti-trust measure which blocked Bannson from expanding his empire.[7] Aaron traveled between the Prefectures of the Republic in his private DropShip, Opportunity, on diplomatic and trade missions; he was noted for his personal wealth.[8] Aaron visited Northwind and later Terra where he saw Tikonov’s Earthwerks Ltd, and signed an expansive deal between multiple Prefectures.

Also during the time prior to the Blackout in August 3132, he was seen exchanging harsh words with Prefect Katana Tormark. He claimed she had a lack of loyalty to the Republic despite her actions in curbing BattleMech smuggling.[9]

After the collapse of the HPG Network in early August 3132[10], Aaron began to use his influence to form his own armed force, the Swordsworn. Using his influence and a regiment of personnel, he started bringing worlds under his influence while not openly admitting rebellion against the Republic. Aaron believed that bringing these worlds under the aegis of House Davion would reward him later on.

Aaron put his cousin, Erik Sandoval-Groell (whom he had helped raise since childhood) into a commanding role in his army. Erik was a leading agent against other renegade Republic splinter factions including his own Prefect Kal Radick's. He first dispatched Erik to Mara, where he was to convince the Sandoval family of Prefecture III to join his Swordsworn group. In response, Christine Sandoval returned Erik back to him on Tikonov.

Aaron then dispatched his disgraced cousin to Achernar in 3133; there his Swordsworn forces on planet would attempt to gain control of a rare functional HPG Station from Republican and Radick's Steel Wolves forces.[11]

In 3134, the Capellan Confederation commenced an incursion into the Republic's Prefectures V and VI. Seeing this as an opportunity gather more worlds under his banner, Aaron offered his Swordsworn to aid in the fight against the Confederation forces. On New Aragon in October, the bulk of Aaron's forces made a blunt attempt to take the planet. Aaron had selected the planet because it was well defended and would be the best place to bloody the nose of the invasion force. Despite his force's success and his swooning support by the planetary governor, he knew efforts to stop the invasion were beyond his ability.[12]

Leaving his Cousin in charge of cleaning up New Aragon, Aaron traveled to Prefecture's VI capital on New Canton. There he attempted to negotiate a defense pact with the Prefecture's government. The New Canton government delayed his talks for days, and Aaron only met with Prefecture's Lord GovernorJose Sebhat once. It wasn't until days later that New Canton's Legate, General Divos Sebhat, announced that the talks were called off. He told Aaron that they were occupied with talks with House Liao officials to sign a non-aggression pact (in which three of their worlds would be surrendered to avoid open conflict on New Canton). He also admitted that he knew the Duke's allegiance to the Republic was questioned, and that he had his own agenda to join House Davion. The Legate then warned Aaron that he only had an hour to leave the planet alive. Aaron and his party made a mad dash through New Canton's capital of Merrick City. After fighting through relentless traffic, they made it to the spaceport and took off in Aaron's flagship, a Union Class DropShip, Kiwanda. During lift off the DropShip experienced an explosion which destroyed the ship's landing gear and damaged the ship's engines. With no help from the ship's captain, Aaron took his bodyguard Ulysses Paxton, his valetDeena Onan, and rushed to the 'Mech bay. There he mounted his modified Black Hawk and had his two employees squeeze into the confines of his 'Mech (the bodyguard crawled into an empty missile bay, and Deena squeezed into a small alcove in the back of cockpit). Aaron was forced to blow open the DropShip's bay door and use his Mech's improved jump jets to fly free from the doomed ship.[13]

Aaron managed to control the descent of his 'Mech so he would land near a reef offshore Barosa Island. Aaron managed to keep his bodyguard alive as he piloted his 'Mech along the shallow reef to the shore. He kept his 'Mech away from the huge wave of his DropShip's crash landing. Once on the isle's shore from Gulf of Emeralds, he made his way to the Island's Spaceport.

Once Aaron got to the Spaceport perimeter, he was attacked by the Spaceport's security forces. His 'Mech was damaged and running hot. Aaron reflected on his situation and wouldn't believe that it was an accident, but rather sabotage that claimed his DropShip. He then offered a reward to any DropShip crew who would aid his escape from New Canton. He was rescued by Captain Gus Clancy with his Excalibur Class DropShip, the Tyrannos Rex.[14]

Captain Clancy used his loading 'Mech to drag Aaron's Black Hawk aboard the Tyrannous Rex while under fire by a pair of security 'Mechs. The 'Rex's guns fended off the attempt to take out the Duke, but Space Port Security 'Mechs hit Aaron's Black Hawk near the cockpit; this injured him as he and his passengers were being pulled aboard.[15]

After liftoff and an escape from the spaceport, Aaron woke up and met the 'Rex's captain. Aaron was amused by Captain Clancy's rough and honest character and negotiated a deal with him to rent out his ship as a flagship.[16]

While Aaron was on the run, the New Canton government began to circulate rumors of Aaron's demise. By October 20th, Aaron managed to counter the circulating news of his death with his own announcement of his survival of an assassination attempt.

Aaron next traveled to Pleione to a Swordsworn Fleet staging area and met with Erik. He revealed to Erik that he had a revelation of how to gather new worlds to their banner. He revealed that the only way he could muster enough forces to fight off the Liao Incursion was to muster sufficient worlds into a Coalition. Aaron said he had decided to utilize the Tyrannous Rex which he converted into a mobile headquarters and palace. He then dispatched Erik to Shensi, where he was to conduct an important diplomatic mission to win world for the Swordsworn. Secretly, Aaron had dispatched Deena to conduct a mission to guarantee Erik's success on Shensi. A Liao mercenary company, St. Cyr’s Grenadiers, attacked Shensi during Erik's negotiating effort, which led to many difficulties.

After parting ways with his nephew, Aaron took the Tyrannous Rex to Azha. While on planet, he had the ship refitted into his envisioned flying palace and command center.

In late November, Aaron arrived with the newly refitted Tyrannous Rex and put on a spectacular show to announce his arrival. On board his ship, he conducted an extensive party for notable government officials as well as local celebrities. He used the planned Liao raid on Shensi to encourage the local government to sign into his coalition of worlds.[17]

On December 5th, his nephew arrived in orbit to meet Aaron's flagship. Erik congratulated him after he heard that Shensi was for their cause, however Erik was distressed to find out that he was sent on a planned mission that would likely have killed him. Aaron then dispatched Erik to take command of Swordsworn forces struggling against the invasion on St. Andre.

Aaron then traveled to Poznan to convince the highly contentious population to join his cause. Before any deal could be made, word arrived that Erik's forces' situation on St. Andre had turned desperate; Aaron then mustered all the troops he could and rushed to aid his nephew's forces.

On December 24th Liao forces began their invasion of the ancient Star League outpost, Fort Ravengale. Aaron's force of four DropShips and numerous 'Mechs hot dropped after destroying Liao reinforcements that were attempting to conduct an orbital insertion against the Fort. He then led his men with a hot drop in his refurbished Black Hawk; this rallied his troops and helped force out Liao forces.[18]

His troops gave him the nickname the Flying Duke, due to his dramatic hot drop insertion to save the fort. After the cleanup, he met with his nephew and told him he had learned of the Liao spy that he had been dealing with. Erik casually told him that he'd taken care of her.[19]

After the Confederation took New Syrtis and Taygeta, they turned their attention to Tikonov. Aaron was on the world at that time, and led the defense in May 3145. The CCAF invaded the world with Warrior House Dai Da Chi and two other regiments. The defending Federated Suns forces prevented the Capellan invasion from being successful, but Aaron Sandoval was killed in action.[1]

Some early information is found in the Republic of the Sphere PDF original appeared in the character WizKids canon website, as a online INN Profile. After the events of the novel Fortress Republic, it is unclear what happened to Aaron Sandoval.

Aaron Sandoval was noted for piloting a customized Dark Age era non-OmniMech version of the Black Hawk BattleMech in 3134. The 'Mech was based on the original version with the addition of Improved Jump Jets. It was painted white with gold highlights.[21]